Photographing birds is the single most challenging area in nature photography. If the jolly things could not fly it would probably help! You must have a telephoto lens - something between 300 mm and 600 mm. Moderate camera skills are essential because birds do not generally allow much time for working out exposure and fine-tuning focus. Fully automatic focus and exposure metering help a lot, as does a motor drive, which lets you take lots of images in just a few seconds. For lenses longer than 400 mm, a tripod will be needed to support the lens. Next on the list is a fast lens and the correct film. I use the fastest lenses I can get, and always ISO 100 film. Slower lenses and faster film are a cheaper option.